Diving is the primary method used by commercial fishers to catch (collect) sea urchins and sea cucumbers. In the illustration above, a SCUBA diver (left) uses a hand rake to put an urchin into a mesh bag. A hookah diver (right) collects a sea cucumber by hand.

Divers use either or SCUBA (self-contained underwater breathing apparatus) or hookah (surface-supplied air gear). They work from vessels specifically outfitted for diving, with a tender onboard overseeing the air system and maintaining the vessel while divers are in the water (Source).

Divers make multiple dives in a day, typically as deep as 60 meters. They collect sea cucumbers by hand. To collect urchins, they use hand rakes, sorting the urchins by size and quality and placing them in a mesh bag while underwater.

Recreational fishermen collect urchins and spiny lobster by diving.

Set longline gear is used to catch Pacific halibut, sablefish, some rockfish species and swordfish. It consists of a ground line that extends horizontally along the seafloor with baited hooks at regular intervals along the line and connected to the surface via a vertical line and marked at each end with a surface buoy, pole, flag and radar reflector (Source). After the gear is left to soak, it is retrieved, the fish removed, and the gear redeployed. Deep-set buoy gear is a variant of set longline gear that is used to target swordfish.

Vertical longline or more rigid stick gear may be used to catch some rockfish species. The vertical longline is weighted on one end and held vertical by a buoy at the sea surface, with several hooks attached at regular intervals, to better catch fish that may stack vertically in the water column or near rocky outcrops or canyon walls. Stick gear consists of a length of PVC pipe with leaders attached at intervals along it, each with a hook at the end, to catch bottom or near-bottom species, especially for the live fish market. Rod-and-reel gear is used by dropping a baited line from a hand-held pole and retracting it using either a mechanized or hand-powered reel.

Troll gear consists of hooks attached to lines deployed from outriggers (long poles) that extend on each side of the boat and are pulled (trolled) through the water to attract the target species, most commonly salmon and albacore.

When trolling for albacore, lures are used, the gear is deployed at or near the surface, and the boat travels at high speeds (5 to 8 knots). When trolling for salmon, bait or lures may be used, the gear is deployed at different depths depending on where the fish are, and the vessel moves at slower speeds (less than 3 knots).

Pole-and-line gear consists of rigid rods or poles with lines typically baited with live bait that fishers use to catch white seabass and California halibut as well as albacore tuna. The bait is stored in a “live well” on the boat until it is needed.

Set gillnet gear is used by commercial fishermen to catch Pacific herring in San Francisco Bay for the sac-roe and fresh fish markets (Source). The gear consists of a single panel of net anchored in shallow spawning areas with weights along the bottom line and floats along the top line (or cork line), holding the net to form a vertical, curtain-like wall of mesh. Herring that become entangled in the net are collected and either processed for their marketable roe or marketed whole for later processing and sale, primarily via export to Japan. Instead of nets, the Pacific herring eggs on kelp (HEOK) fishery uses rafts or cork lines with giant kelp, Macrocystis pyrifera, attached. The gear with suspended kelp is set in shallow areas where herring spawning is expected to occur. Once egg coverage on the suspended kelp reaches a marketable amount of spawning has ended, the egg-coated kelp blades are collected, and the eggs are removed, processed and exported to Japan.

Drift gillnets have been used to catch some highly migratory species such as swordfish and thresher sharks. However, permits for drift gillnet gear were to be phased out by January 2023. With this gear, the net is fixed to the back of a fishing boat and drifts underwater behind it. Drift gillnets often are deployed at night and retrieved at dawn. The mesh size differs for each fishery. Drift gillnet fishing had been allowed only in federal waters (3-200 miles offshore).

Purse seines are used to catch tuna, market squid, and coastal pelagic species, including northern anchovy, Pacific (jack) and chub mackerel, and Pacific sardine.

The purse seine is a type of roundhaul or encircling net gear. The net has floats or buoys made of cork on the top and a weighted lead line on the bottom that holds it in position. A skiff is used to deploy the net, encircling a school of fish or squid alongside the fishing boat (purse seiner). The lead line is pulled to the boat to purse the bottom of the net closed. The catch is then pumped (or sometimes scooped) out of the net and into the boat’s fish hold.

When fishing for squid, fishermen use high-intensity lights to attract and aggregate squid near the ocean surface where they are more easily caught. These lights are attached to the purse seine vessel itself or a smaller vessel known as a light boat.

A trawl is a funnel-shaped net that is towed behind a fishing boat. The closed tail end, known as the cod end, is where the fish are collected. Trawl gear, mesh size, configuration and tow times vary by area fished, species sought (groundfish, halibut, shrimp), and intended market (live or fresh).

The net is attached in most cases to trawl doors (or otter boards), which act as wings, helping to keep the net open horizontally while the net is pulled through the water. A floatline on the top and a footrope on the bottom of the net create a vertical opening through which the fish are caught. A bycatch reduction device (BRD) is used to enable many non-target marine species to escape the net.

Bottom trawl gear is used to groundfish along or near the seafloor. Gear variations include large and small footrope trawls, and Danish or Scottish seines, which do not have doors. Targeted species include flounders, soles, rockfish, lingcod, skate.

Note: Midwater trawls use a smaller mesh net compared to groundfish bottom trawls and are towed through the water column, with little or no contact with the bottom. Midwater trawls are not used widely in California because the target species (hake, widow rockfish, yellowtail rockfish) are found primarily off the coast of Oregon and Washington.

When bottom trawl gear is used to target shrimp (pink shrimp in northern California, ridgeback shrimp in southern California), it can be either single or double rig, meaning one or two nets. The gear usually is towed suspended off the bottom. A lightweight tickler chain, which periodically hits the bottom, is sometimes used to get the shrimp off the bottom and into the net. A boom is used to haul the trawl net(s) out of the water after a tow. After the catch is released onto the deck, it is sorted into bins for storage, which then are unloaded dockside at the end of a fishing trip.

Commercial fishermen use crab traps (above) and lobster traps (below) made of steel mesh with entry and escape ports designed to allow undersized crabs and lobsters to escape. Baited traps are set on the seafloor either singly or in strings, marked with buoys. They are left in the water for up to a few days before being retrieved using a hydraulic winch. The catch is placed in holds or aerated tanks on the boat, and then delivered live dockside.

Recreational fishermen catch Dungeness crab, rock crab, and spiny lobster with traditional hoop nets, which lie flat on seafloor until an attached line is pulled to the surface, and rigid conical hoop nets. Traps are set from private vessels, charter vessels (typically while also hook-and-line fishing for rockfish), or docks or other shoreside structures, and are left to soak for 30 minutes to a few days before being retrieved.

Fish traps or pots are used by commercial fishermen to catch various finfish species. Depending on the species targeted, they are square, rectangular, or basket-shaped and are equipped with a funnel (opening) located along the side to allow fish to swim into the trap and an escape port to allow smaller and other non-target animals to exit. For sablefish fishing, conical pots or rectangular traps that are larger, heavier, and shaped differently compared to other trap gear are used. As with crab traps, fish traps are attached by rope to marker buoys and set in strings, left to soak for some time before being retrieved to collect the catch and deliver it shoreside.

Bucket and barrel (or Korean-style) trap gear is used by commercial fishers to target hagfish (Source). Bucket gear consists of a five-gallon plastic bucket with an entry funnel on top whereas a barrel or Korean-style trap is a cylindrical container with an entry funnel on both ends. Both gear types have holes of the same diameter along the sides of the trap. The holes allow water to flow through the trap, helpful for deploying and retrieving the gear, allowing additional entry—and escape of smaller—hagfish.